Topic summary

Excipient function in a licensed injectable

Pharmacology › Formulation chemistry bacteriostatic water cloudy or discoloured solution sterile water Solved Wiki Closed

This is a generated summary. It shows the 5 most-liked posts from a topic of 8, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.

vial_slopeTL3Regular23 Mar 2025#1

Excipient function in a licensed injectable Writing it up because I had to work it out twice and would rather nobody else did.

I was wrong about excipient function in a thread last spring and I would like to correct it publicly rather than quietly.

The error was in the units, which changed the conclusion by an order of magnitude. Setting out the corrected version, and the way I now check for that class of mistake.

26 likes 16mo

e.mikkelsenTL2Member8 Apr 2025#2

Excipient identity should be on the document and rarely is. A vial containing bulking agent and a vial containing only peptide behave differently on reconstitution and weigh differently.

5 likes 16mo

cannula_notesTL2Member28 Apr 2025#4

e.mikkelsen, post #2: Excipient identity should be on the document and rarely is. A vial containing bulking agent and a vial containing only peptide behave differently on reconstitution and weigh differently. Go to post

Community wiki post. Any member at trust level 3 or above can edit this post; every edit is recorded. Last edited by o.lindgren on 21 Sep 2025.

3 May 2025 — formulary_notes: Replaced an unsourced figure with the published one and cited it.
21 Sep 2025 — o.lindgren: Removed a claim that the cited source did not support.

Editors: formulary_notes, o.lindgren

Isotonicity: an isotonic solution has the same osmotic pressure as blood. Non-isotonic solutions can cause discomfort on injection. Injectable peptide solutions are formulated to be isotonic.

If anyone can point at the primary source I would be grateful.

28 likes in reply to #2 15mo

r.oyelaranTL2 Solution7 May 2025#5

vial_slope, post #1: Excipient function in a licensed injectable Writing it up because I had to work it out twice and would rather nobody else did. I was wrong about excipient function in a thread last spring and I would like to correct it publicly rather than quietly. The error was in the units, which changed the conclusion by an order of magnitude.… Go to post

Surfactants such as polysorbate are added to prevent adsorption and aggregation at interfaces. In a bare research preparation there is nothing performing that function.

20 likes in reply to #1 15mo

k.farrugiaTL3Regular15 May 2025#6

Useful. I had the fact and not the reason, which turns out to be the important half.

8 likes 14mo

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This topic was closed 45 days after the last reply. Closing is automatic for quiet topics so that a settled answer does not collect new questions underneath it. If you have a follow-up, open a new topic and link back to this one — that keeps both readable and gives your question its own title.

Moved from Pharmacokinetics by dr_okonkwo. Category placement is not obvious from outside and getting it wrong is expected. This topic will get better answers here. The move is recorded in the public log citing R7.

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